When its hot and dry or windy, you sweat but it evaporates really fast so you think you arent sweating much because you are still dry. Even more important to replace both water and lytes!

There are some small packets you can mix in your water bottle that have absolutely NO taste to them - if you really can't stomach all the flavored stuff, these might be a good option. Even with all the ades and lytes, you still need water too.

You are lucky! Hyponatremia is dangerous for a lot of reasons. Humans just dont tolerate very low or high levels of any salt - and it doesn't take much to throw things WAY out of whack. It's pretty amazing that our bodies let us do the things we do to them!